Changing laws of formation pressure of constant-volume fractured enclosed reservoirs under the hydraulic pressure of drilling fluid

被引：0
|
作者：
Zhao X. [1 ,2 ]
Meng Y. [2 ]
Yang S. [1 ]
Wei N. [2 ]
Li G. [2 ]
He Q. [1 ]
机构：
[1] Sinopec Research Institute of Petroleum Engineering, Beijing
[2] State Key Laboratory of Oil and Gas Geology and Exploitation, Southwest Petroleum University, Chengdu, 610500, Sichuan
来源：
Meng, Yingfeng (cwctmyf@swpu.edu.cn) | 2018年 / Natural Gas Industry Journal Agency卷 / 38期
关键词：
CFD; Constant-volume enclosed system; Formation pressure; Fracture; Laboratory test; Liquid–liquid gravity displacement; Pressure relief method; simulation; Well killing;
D O I：
10.3787/j.issn.1000-0976.2018.06.012
中图分类号：
学科分类号：
摘要：
The complex situation of leakage and blowout coexistence often occur during the drilling of fractured strata. At present, their mechanisms are described only based on experience without basic theoretical studies or model descriptions. In this paper, a great number of actual drilling, logging and testing data of the Yada Oil Field in Iran were taken as an example to carry out simulation experiments and CFD single-fracture constant volume simulation verification on the liquid-liquid constant volume displacement behavior by means of the visual liquid-liquid displacement experiment device based on the real fractures. Then, the influential laws of drilling fluid density, wellhead back pressure and crack width on formation pressure were analyzed. And the following research results were obtained. First, with the increase of drilling fluid density, the displacement phenomenon gets more and more obvious and the formation pressure drops rapidly. And as the displacement goes, the formation pressure is basically constant. Second, the formation pressure increases gradually with the increase of back pressure. Third, the formation pressure rises gradually to the maximum value when high-density drilling fluid reaches the crack plate. And as the displacement goes, the formation pressure reaches a new balance. Fourth, the wider the crack is, the greater the formation pressure changes, the less affected the displacement form is by the morphology of crack surface and the faster the displacement advancing is. It is concluded that the formation pressure of constant-volume oil/gas reservoirs is positively related to the drilling fluid density and back pressure. Therefore, it is recommended to combine plugging with wellhead pressure control in drilling and to apply the pressure relief method to well killing. © 2018, Natural Gas Industry Journal Agency. All right reserved.
引用
收藏
页码：91 / 96
页数：5
相关论文
共 19 条
  • [1] Zhang J., Well killing technology for wells with blowout and lost circulation coexisting, Drilling and Production Technology, 31, 5, pp. 30-33, (2008)
  • [2] Zeng M., Zeng S., Mao J., Treating techniques of blowout-lost circulation coexistence in gas hole drilling, Natural Gas Industry, 25, 6, pp. 42-44, (2005)
  • [3] Wang P., Luo P., Nie X., Zhang X., Yang L., Dealing with complex conditions on well Shuangmiao-1 with both lost circulation and underground blowout, Natural Gas Industry, 27, 1, pp. 60-63, (2007)
  • [4] Warren J.E., Root P.J., The behavior of naturally fractured reservoirs, SPE Journal, 3, 3, pp. 245-255, (1963)
  • [5] Kazemi H., Seth M.S., Thomas G.W., The interpretation of interference tests in naturally fractured reservoirs with uniform fracture distribution, SPE Journal, 9, 4, pp. 463-472, (1969)
  • [6] Shu G., Meng Y., Li G., Wei N., Zhao X., Yang M., Mechanism of mud loss and well kick due to gravity displacement, Petroleum Drilling Techniques, 39, 1, pp. 6-11, (2011)
  • [7] Jia H., Mechanism study on well kick accompanied with lost circulation during drilling fractured formation, (2013)
  • [8] Zhao X., Meng Y., Hou X., Yang S., Bao H., Li G., Pattern and control of gravity displacement between asphaltic heavy oil and drilling fluid, Oil Drilling and Production Technology, 38, 5, pp. 622-627, (2016)
  • [9] Zhang Z., Research on the rule of gravity displacement in fracture gas reservoir, (2008)
  • [10] Chang L., Gao Y., A simple numerical method for contact analysis of rough surfaces, Journal of Tribology-Transactions of the ASME, 121, 3, pp. 425-432, (1999)
12